Correct Option: B

Protein digestion begins in the stomach with the action of pepsin. Pepsin is the active protein-digesting enzyme of the stomach. When pepsin acts on the protein molecule, it breaks the bonds that hold the protein molecule together, called peptide bonds. Once broken, peptide bonds yield chains of amino acids linked together called polypeptides that are digested in the small intestine with the help of trypsin, chymotrypsin, and carboxypeptidase.